spelling fixes: arch/um/

Spelling fixes in arch/um/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 76fe0b0..83bf15a 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -35,7 +35,7 @@
 /*
  * Returns the free space inside the ring buffer of this line.
  *
- * Should be called while holding line->lock (this does not modify datas).
+ * Should be called while holding line->lock (this does not modify data).
  */
 static int write_room(struct line *line)
 {